The Noorderkerk (North Church) was built in 1623, the final masterpiece of Hendrik de Keyser . The square surrounding the church is the site of a sprawling flea market on Saturday, where stalls are a mixed bag of decent paintings, a few antiques, handmade jewelry, rugs, and old books at rock-bottom prices. Everything starts to close up around 2pm so get there at 9am to snap up some great vintage finds. The Boerenmarkt is adjacent.